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Abstract:

An inflatable curtain airbag includes a luminescent visual marking
indicating a proper installation of a compacted airbag bundle.
Luminescent materials, when exposed to electromagnetic radiation of one
frequency range, emit electromagnetic radiation in a different frequency
range. This emitted radiation can be automatically detected by an optical
detection device. The simplest marking consists of a line extending along
the length of the airbag bundle. To facilitate recognition of the marking
in an automated quality control, the marking may consist of a number of
parallel lines, a portion of which may be broken lines, or a row of dots
lined up along the length of the bundle. When the curtain airbag is
compacted to a bundle, the marking may be located anywhere on the surface
of the bundle in an area facing the interior of the vehicle.

Claims:

1. An airbag assembly, comprising: an inflatable curtain in a compacted
state having a gas inlet for receiving an inflation gas and at least one
mounting device for mounting the inflatable curtain in a vehicle along a
length of the inflatable curtain; and at least one luminescent marking
extending along the length of the inflatable curtain in a location
accessible to an optical detection device after mounting the airbag in
the vehicle, the marking being detectable by the optical detection
device, the marking displaying a proper shape upon a proper installation
in the vehicle and an improper shape upon a twisted installation in the
vehicle.

2. The airbag assembly of claim 1, comprising two of the markings
extending on two opposing surfaces of the curtain, of which at least one
is accessible to the optical detection device on the curtain in the
compacted state.

3. The airbag assembly of claim 1, wherein the at least one marking is
applied to the curtain prior to compacting the curtain into a bundle.

4. The airbag assembly of claim 1, wherein the at least one marking is
applied to the curtain after compacting the curtain into a bundle.

5. The airbag assembly of claim 1, further comprising a wrapper
surrounding the compacted curtain, the wrapper bearing the at least one
marking.

6. The airbag assembly of claim 1, wherein the at least one marking
includes an array of parallel lines.

7. The airbag assembly of claim 1, wherein the at least one marking
includes a luminescent pattern.

8. The airbag assembly of claim 1, wherein the at least one marking is
printed.

9. The airbag assembly of claim 1, wherein the at least one marking is
painted.

10. The assembly of claim 1, wherein the at least one marking consists of
a phosphorescent material.

11. The assembly of claim 1, wherein the at least one marking consists of
a fluorescent material.

12. The airbag assembly of claim 1, further comprising that the curtain
in the compacted state is a rolled bundle with the at least one marking
extending along the length of the rolled bundle on an outer layer.

13. The airbag assembly of claim 1, further comprising that the curtain
in the compacted state is a folded bundle with the at least one marking
extending along the length of the folded bundle on an outward-facing
fold.

14. The airbag assembly of claim 1, wherein the marking in the proper
shape comprises at least one continuous marking section that is
interrupted in the improper shape.

Description:

FIELD OF THE INVENTION

[0001] The present invention relates to an inflatable curtain airbag
assembly with an aid to verify proper installation in a vehicle.

BACKGROUND OF THE INVENTION

[0002] Inflatable safety restraint devices, or airbags, are well accepted
for use in motor vehicles and have been credited with preventing numerous
deaths and injuries. Inflatable airbags are now mandatory on most new
vehicles. Airbags are typically installed as part of a system with an
airbag module in the steering wheel on the driver's side of a car and in
the instrument panel on the passenger side of a car. In the event of an
accident, a sensor within the vehicle measures abnormal deceleration and
triggers the ignition of an explosive charge contained within an
inflator. Expanding gases from the charge travel through conduits and
fill the airbags, which immediately inflate in front of the driver and
passenger to protect them from harmful impact with the interior of the
car.

[0003] Side impact airbag systems have also been developed in response to
the need for similar protection from lateral impacts between a passenger
and the side of a vehicle's interior. This might occur when another
vehicle collides with the side of the car, or in a rollover situation
where the side of the car is repeatedly impacting the ground. One form of
these airbags, provided for the protection of the head and upper torso of
an occupant and commonly referred to as "inflatable curtains," may be
mounted on or near the roof rail, or a portion of a vehicle frame that
extends along a length of the vehicle between the side windows and the
roof.

[0004] An inflatable curtain airbag is typically compacted by folding,
rolling, or a combination of both rolling and folding, to create a
tube-shaped bundle for stowing the cushion behind a headliner covering
the interior of the roof of the vehicle. The curtain airbag is typically
designed to unroll or unfold downward from the roof of the vehicle during
inflation and becomes positioned on the outboard side of the occupant.
Generally, the inflatable curtain airbag is sized to descend below the
window sill. Consequently, when not inflated, the curtain airbag includes
a significant amount of material. This material is then rolled, folded,
or otherwise gathered to form a tight, tubular bundle, which must be
packed into a small packaging space. A wrapper may be added to ensure
that the curtain airbag is kept rolled or folded.

[0005] The compacted curtain airbag is then mounted either on or close to
a roof rail of the vehicle. A metal gas guide that extends from the
inflator is then connected to an inlet port of the inflatable curtain.

[0006] Once the curtain airbag has been rolled or folded into the bundle,
it is important that the curtain airbag is installed properly. The soft,
pliable material of the airbag makes it possible that it is installed in
an improper, twisted manner that may remain unnoticed. Installing the
curtain airbag in a twisted configuration, however, may be detrimental to
the proper function the curtain airbag.

[0007] In an attempt to reduce the likelihood that the inflatable curtain
will be installed in a twisted manner, it has been proposed to provide
alignment lines or other similar markings that give a visual guide to a
person installing, inspecting, or servicing the airbag, thus helping to
avoid or retroactively detect a twisted installation of a curtain airbag.
Manually detecting a twisted or entangled installation of the airbag,
however, requires additional time and labor and thus adds to the costs of
installing curtain airbags.

[0008] It has also been suggested to provide a stiffening member built
into the curtain airbag along its length that prevents twisting and
retains the shape of the curtain airbag bundle. Such a stiffening member,
however, adds to the bulk and weight of the airbag module. Also, the
stiffening member complicates the installation of the curtain airbag
because the thus reinforced bundle has a significant length that cannot
be reduced by folding it due to its stiffness.

SUMMARY OF THE INVENTION

[0009] Accordingly, a need exists for an inflatable curtain airbag
assembly that provides an easy and low-cost solution to ensure a proper
installation and detection of a twisted installation, particularly during
installation or automated quality control. It is particularly desirable
to reduce labor costs while consistently ensuring proper installation.

[0010] The present invention meets this need by providing an inflatable
curtain assembly that includes a luminescent visual marking that may be
fluorescent or phosphorescent and that indicates a proper installation.
Luminescent materials, when exposed to electromagnetic radiation of one
frequency range, emit electromagnetic radiation in a defined frequency
range, either at the same time (fluorescence) or for a duration extending
beyond the time at which the electromagnetic energy is absorbed
(phosphorescence). The emitted radiation can be automatically detected by
an optical detection device. Such detection devices use sensors that are
inexpensive and reliable. The emitted radiation of the marking may be in
the visible light spectrum to make it detectable to the human eye and to
an automatic optical detector alike. The luminescent material may absorb
electromagnetic radiation in the UV spectrum, for instance so-called
black light.

[0011] The simplest marking consists of a line extending along the length
of the airbag bundle. Such a line can be manufactured by weaving a
luminescent thread into the airbag material. The thread has been dyed
with a luminescent dye before weaving. The marking may also be applied to
an assembled curtain airbag by painting or printing so that the
unprocessed airbag fabric itself does not need a marking specific to an
individual type of airbag. To facilitate recognition of the marking in an
automated quality control, the marking may consist of a number of
parallel lines, a portion of which may be broken lines, or a row of dots
lined up along the length of the bundle. When the curtain airbag is
compacted to a bundle, the marking may be located anywhere on the surface
of the bundle in an area facing the interior of the vehicle or in an area
accessible to an optical inspection after installation.

[0012] In one configuration according to this invention, the inflatable
curtain airbag is rolled into a bundle. For such a bundle, the surface of
the bundle is formed by portion of the curtain airbag that is proximate
to fastening structures for mounting the curtain airbag on one side of
the curtain airbag. The marking can be applied before compacting the
curtain airbag because the surface of the bundle facing the vehicle
interior is known before compacting.

[0013] In another configuration according to the invention, the inflatable
curtain airbag is folded into a bundle. The surface of the folded bundle
is formed by narrow stripes of airbag fabric. Variances in folding the
airbag may make it harder to determine in advance which portions of the
airbag fabric will be forming the surface of the bundle after compacting.
In such a case, the marking may be applied with luminescent paint or ink
after folding the curtain airbag to a bundle.

[0014] Further details and advantages become apparent from the following
description of exemplary embodiments illustrated in the attached
drawings. The drawings are included for illustrative purposes only and
are not to be considered to limit the scope of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In the drawings,

[0016] FIG. 1 is a plan view of one embodiment of an inflatable curtain
airbag in an unfolded state;

[0017] FIG. 2 shows the curtain airbag of FIG. 1 rolled up in a bundle
properly installed in a motor vehicle;

[0018] FIG. 3 shows the curtain airbag of FIG. 1 rolled up in a bundle
improperly installed in a motor vehicle;

[0019] FIG. 4 shows a sectional view through the curtain airbag of FIGS.
1-3; and

[0020] FIG. 5 shows sectional view through an alternative embodiment of a
compacted curtain airbag of the present invention.

DETAILED DESCRIPTION OF THE DRAWINGS

[0021] In FIG. 1, a curtain airbag 1 according to at least one embodiment
is shown in a non-inflated and unfolded state. At its upper section 2,
the curtain airbag 1 exhibits a number of retaining means in the form of
mounting tabs 4, which are used for fixing of the curtain airbag 1 in the
side roof frame area of a motor vehicle. Furthermore, curtain airbag 1
exhibits an inflatable protection area 27 which is linked with a gas
generator 25 by means of its filling channel 26. Gas generator 25 is
connected with airbag 1, for example, in the front area of the upper
section 2 and may also be connected with a sensor and evaluation unit, so
that it is activated if a side or rollover accident is sensed and thereby
inflates curtain airbag 1. Gas generator 25 in this case conducts the gas
directly into the filling channel 26, which guides the gas into the
respective chambers. Alternatively, the gas generator 25 can be connected
with a filling tube or filling pipe which is inserted into filling
channel 26. This allows both the airbag fabric and the seams to be
protected from the hot gas streaming out of the gas generator.

[0022] The inflatable protection area 27 is divided into a number of
chambers 5, 6, 7, 8, and 9 which are divided from one another by darts or
stitchings 10, 11, 12, and 13. Chambers 5, 6, 7, 8, and 9 are arranged in
such a way that a front section of the protection area is formed for the
front seats of a motor vehicle by means of chambers 7, 8, and 9 and a
rear section of the protection area is formed for the rear seats of a
motor vehicle by chambers 5 and 6. Between the front section and the rear
section a non-inflatable section 14 is formed in an area which no vehicle
occupant can typically reach during the accident. This can be in the area
of a vehicle B pillar, for example.

[0023] Two guide chambers 15 and 16 are provided in the upper section 2 of
curtain airbag 1, which are connected in one piece with the protection
area and which project over upper section 2. They are connected from the
point of view of gas flow with filling channel 26 of curtain airbag 1, so
that the gas which is created by gas generator 25 can enter quickly into
guide chambers 15 and 16. Guide chambers 15 and 16 may be each located
between two mounting links 4 whereby front guide chamber 15 is allocated
to the B pillar area of the vehicle and rear guide chamber 16 is
allocated to a C pillar area of the vehicle when in a mounted state.

[0024] A horizontal marking 19 extends along the entire length of the
airbag 1 near the mounting tabs 4. The marking 19 consists of a
luminescent material that is produced by weaving a luminescent thread
into the airbag fabric. The luminescence may be due to a fluorescent or a
phosphorescent property of the thread. But the marking 19 may also be
painted or drawn with a stroking utensil like a paintbrush or a marker,
or printed or stamped onto the fabric of the airbag 1 by contact with a
utensil transferring a printing line or pattern. The material of the
marking 19 emits electromagnetic radiation in a frequency that is
distinguishable by an automated optical detection device 29 (as indicated
in FIG. 4) from the color of the airbag fabric. The marking 19, shown in
the drawing as a textured line, may have other distinguishing features in
its appearance, such as constituting an array of parallel lines or dots
lined up like a string of beads, or any other shape that gives it a
unique appearance enhancing optical machine detection. While the marking
19 is shown to extend along the entire length of the airbag 1, it may
only be applied in areas between two adjacent tabs 4 or in areas where a
twisted installation of the airbag 1 would otherwise be hard to detect.
The location of the marking 19 is shown for illustrative purposes only.
As will become evident below, the marking 19 may be located at any
distance from the tabs 4 that is visible after compacting the airbag 1
and fixed to a vehicle.

[0025] FIG. 2 illustrates the embodiment of the curtain airbag 1 of FIG. 1
in its compacted state, which may be folded or rolled. The orientation of
the airbag 1 corresponds to the mounted position in the roof frame area
of the vehicle. Mounting links 4 project away from rolled curtain airbag
1 and point downwards. Thus, the fixing points by means of which curtain
airbag 1 is fixed to the roof may be located underneath the folded roll.

[0026] A plurality of retaining straps 20 extending like a cover around
the rolled curtain airbag 1 may be assigned to the mounting links 4,
which hold the airbag in its rolled state. The retaining straps 20 may be
configured to tear when the curtain airbag 1 is inflated. A perforation
can be provided for this purpose, or the material thickness can be
correspondingly thinner. As an alternative to straps 20, a single wrapper
can be provided which corresponds to the length of curtain airbag 1. If a
continuous wrapper is used, the marking 19 may be applied to the wrapper,
or the wrapper may be translucent so as to allow the optical detection
device 29 to detect the marking 19 through the wrapper.

[0027] In FIG. 2, the airbag has been properly installed in a vehicle
without twisting. The proper installation is evident from the
continuously visible marking 19 that is only interrupted by the retaining
straps 20. The automatic optical detection device 29 can be programmed to
memorize the locations of the retaining straps 20 in order to account for
interruptions in the detection of the marking 19 caused by the retaining
straps. Accordingly, during an automated quality inspection, the optical
detection device 29 detects the continuous course of the marking 19
across the entire length of the marking and confirms proper installation
of the airbag 1.

[0028] In contrast to FIG. 2, FIG. 3 shows the airbag 1 of FIG. 1 after a
twisted installation in a vehicle. Notably, the marking 19 does not form
a continuously visible line or string, but leaves voids 28 between
adjacent retaining straps 20. The optical detection device 29, programmed
to account for interruptions in the marking 19 that correspond to the
retaining straps 20, recognizes that the voids 28 are gaps in the marking
19 that are due to improper installation. Accordingly, the optical
detection device 29 gives an alert indicating that the airbag 1 is
twisted.

[0029] FIG. 4 illustrates a section through a compacted airbag 1. In the
embodiment of FIG. 4, the airbag 1 is rolled up and tied together with
straps 20. The compacted curtain airbag 1 shown in cross section may
exhibit a letter "p"-shaped form. Mounting tab 4 is located in front of
guide chamber 15, which is pointing downwards. The inflatable protection
area 27 is folded together as a roll. It can be seen that curtain airbag
1 is attached to the vehicle with its tabs 4 so that the markings 19 face
toward the inside of the vehicle. Accordingly, at least one of the
markings 19 is arranged on a surface that is exposed after mounting the
airbag in a vehicle so that the optical detection device 29 is able to
verify a proper installation. An optional light source 30, such as a
black light, may illuminate the bundle to activate the luminescent
activity of the markings 19. The depiction of the optical detection
device 29 and the light source 30 serves for symbolic purposes only and
is not meant to specify any appearance or shape of the optical detection
device 29 and light source 30 used to implement the present invention.

[0030] In FIG. 4, the marking 19 is applied twice to illustrate possible
locations of the marking 19. Only one marking 19 is required for the
present invention, but the invention is not limited to only one marking
19. On a symmetric airbag 1 that is rolled up from the bottom in opposing
directions for mounting on opposite sides of the vehicle, two markings 19
may be applied on opposing outer surfaces of the airbag 1 so that one of
the markings is detectable by the optical detection device 29, possibly
supported by the light source 30, regardless of the direction in which
the airbag 1 is rolled up for compacting.

[0031] Now referring to FIG. 5, a compacted airbag 1 is shown that has
been folded into a bundle for mounting in a vehicle. Not shown are straps
20 or a wrapper applied to retain the compacted shape of the airbag 1. As
is evident from the markings 19, the locations of the markings 19 are not
limited to the proximity of the tabs 4, but may be arranged in any place
where the airbag surface faces outward. In the embodiment shown, the
airbag 1 may be mounted on the left side of the figure or the right side.
If the airbag 1 is mounted on the left side, the markings 19 applied on
the right side remain visible for an optical inspection by an optical
detection device. If the airbag 1 is mounted on the right side, the
marking 19 on the left side is accessible for an optical inspection by
the optical detection device 29. The indicated locations of the markings
are shown for exemplary purposes only. One marking applied in a location
exposed to the outside of the bundle and thus accessible for inspection
after fixing the airbag 1 in a vehicle is sufficient. For added
flexibility in the choice of a mounting position of the airbag 1, several
marking 19 may be applied.

[0032] If folding the airbag 1 involves variances in locations of creases,
the marking 19 may be applied to the compacted airbag 1 after folding.
That way, it is ensured that the marking 19 is located on the outside of
the folded airbag 1 where it is accessible for inspection. The marking 19
may be sprayed on, stamped, or applied with a marker pen or applied by
any other method that is suitable for reliably transferring luminescent
paint, ink, or dye onto the airbag material.

[0033] The foregoing description of various embodiments of the invention
has been presented for purposes of illustration and description. It is
not intended to be exhaustive or to limit the invention to the precise
embodiments disclosed. Numerous modifications or variations are possible
in light of the above teachings. The embodiments discussed were chosen
and described to provide the best illustration of the principles of the
invention and its practical application to thereby enable one of ordinary
skill in the art to utilize the invention in various embodiments and with
various modifications as are suited to the particular use contemplated.
All such modifications and variations are within the scope of the
invention as determined by the appended claims when interpreted in
accordance with the breadth to which they are fairly, legally, and
equitably entitled.

Patent applications by Charles Richards, Farmington, UT US

Patent applications in class Mounted in vehicle and positioned laterally of occupant

Patent applications in all subclasses Mounted in vehicle and positioned laterally of occupant